<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=\, initial-scale=1.0">
    <title>Document</title>

    <style>
        ul{
            list-style: none;
        }
        li{
            width: 200px;
            height: 50px;
            border: 1px solid rebeccapurple;

        }
        ul:hover li:nth-child(1){
                width: 600px;
                transition: all 2s linear;
               
        }
        ul:hover li:nth-child(2){
                width: 600px;
                transition: all 2s ease;
            
        }
        ul:hover li:nth-child(3){
                width: 600px;
                transition: all 2s ease-in;
            
        }
        ul:hover li:nth-child(4){
                width: 600px;
                transition: all 2s ease-out;
            
        }
        ul:hover li:nth-child(5){
                width: 600px;
                transition: all 2s ease-in-out;
            
        }
        ul:hover li:nth-child(6){
                width: 600px;
                transition: all 2s cubic-bezier(0,.69,1,.19);
            
        }

    </style>

</head>
<body>
    <div>
        <ul>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
            <li></li>
        </ul>

    </div>
</body>
</html>